Amorphous solid

Composite number

Electrochemistry

Metallurgy

Materials science

Cathode

Coating

Layer (electronics)

Silicon

Carbon fibers

Cathodic arc deposition

Vacuum arc

Physical chemistry

Cathodic protection

Medicinal chemistry

Nanotechnology

Organic chemistry

Doping

Thin film

Trimethylsilane

Composite material

Tribology

Chemistry

Electrode

Optoelectronics

Diamond-like carbon

Amorphous carbon

Scientific Reports

In this study, silicon (Si) was doped on a tetrahedral amorphous carbon (ta-C) coating and the tribological characteristics of the resulting Si-doped diamond-like carbon (DLC; a-C:Si:H) were investigated against a SUJ2 ball. The Si fraction in the coating was varied from 0 to ~ 20 at.% by increasing the trimethylsilane gas flow rate during filtered cathodic vacuum arc deposition. The coefficient of friction (CoF) showed no obvious change when the Si fraction was less than ~ 7 at.%. However, after Si doping, it significantly decreased when the Si fraction was greater than ~ 8 at.%. The running-in period also decreased to less than 1000 cycles after Si doping. The rapid formation of Si-rich debris and transfer layer led to the fabrication of a low-friction tribofilm, which was induced by the tribochemical reaction with moisture under ambient conditions. When the Si fraction was ~ 17 at.%, the lowest CoF of less than 0.05 was obtained. Further Si doping beyond the critical point led to the destruction of the film because of reduced hardness.

Effects of silicon doping on low-friction and high-hardness diamond-like carbon coating via filtered cathodic vacuum arc deposition